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5 transient voltage protection, Ransient, Oltage – Maxim Integrated Secure Microcontroller User Manual

Page 91: Rotection

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Secure Microcontroller User’s Guide

91 of 187

10.5 Transient Voltage Protection

The microprocessor provides protection from transients through a built in power-fail/power-on reset and
Watchdog Timer. Each of these functions should be initialized by the user as part of the reset routine. The
following code demonstrates the set up for a user that will support the Watchdog function.

TA

EQU

0C7h


ORG

00h

SJMP

Start


Org

30h

Start :

MOV

TA,

#0Aah

;Timed

MOV

TA,

#55h

; Access

ORL

IP,

#80h

;Set RWT to restart the Watchdog Timer


MOV

TA,

#0Aah

;Timed

MOV

TA,

#55h

; Access

ORL

PCON,

#44h

;Set POR (PCON.6) bit for power-on reset detect

; and enable Watchdog Timer by setting EWT

(PCON.2)